Cat Leg Injury

File: IMG_0473.jpg (2MB, 3264x2448px) Image search: [Google]

2MB, 3264x2448px

Sup lads, im in need of some advice from someone more knowledgable about cats than me.
My cat here recently had a nasty fall, i saw her land and heard a loud crack noise. I rushed her to the vet, got xrays done and everything, for them to tell me that nothing whatsoever is wrong.
I thought that due to the crack, she might have torn a tendon or damaged a joint, but the vets didnt really want to hear that and told me that none of her bones are broken so shes fine.
She seemed to be doing better and her limp went away almost completey, but an hour ago she came up to me, growling and limping worse than before. She must have re-injured whatever it is in her leg that was bad, and shes in pretty bad pain it seems.
What the hell can I do, and what could her injury be? I locked her in my room away from her brother with food and litter but i really want to help treat her pain.